Friday, November 27, 2015


text and photos by Bruce McDonald

A few snippets from some recent rambles.

Beetles on a Gower beach
First Whiteford on Gower, which Cardiff Naturalists' last visited to look at beetles a few years back with Steve Bolchover. A fine day in mid-June this year and the same stretch of sand on the edge of the dunes around SS 4428/9517 was productively revealing. The key appears to be to find a larger plank of wood or branch or tree trunk that is just above the recent high-tide mark but below the dunes. Lift slowly and see what lies beneath. The black beetle, Broscus cephalotes, was found quite easily. They either stayed put or went scuttling off across the beach.

Broscus cephalotes

Not so common but also in evidence was Nebria complanata, sufficiently rare to warrant its own Species Action Plan. It feeds on sandhoppers at night and is variously referred to as the Strandline Beetle (as is Broscus cephalotes!) or Beachcomber Beetle. Have your camera ready if you find one under timber as they often burrow down into the sand.

Nebria complanata

Running around on the surface of the beach in the same area was the Dune Tiger Beetle, Cicindella hybrida, and helping to procreate the species were the two below. They can travel at speed so are not always easy to photograph but these two had other things on their minds.
Dune Tiger Beetle (Cicindella hybrid)

Galls on Gower and at Culverhouse Cross
Whilst on Gower another gall to add to the existing 'collection'. This I take to be Aulacidea hieracii described as having ovoid or elongate swelling of the stem, green at first then hard and brown. This was on several Hawkweed plants in the car park at Oxwich Bay.

Gall on Hawkweed

The Copthorne Hotel at Culverhouse Cross roundabout, Cardiff, has the usual common shrubs and trees but the Hawthorn was showing examples of the gall shown below. It has been a struggle to identify this one and any expert views would be most welcome. Photographic comparison with web images suggests Gymnosporangium as a possibility - caused by a fungus. Whereas clavariiforme is usually associated with Juniper which does not seem to apply here, this could be confusum.
Gall on Hawthorn

... and not far away some Holm Oaks, Quercus ilex, with the gall shown below. Again, information on galls affecting this oak is limited, the main reference being to Aceria ilicis. caused by a mite.

Gall on Holm Oak

The next challenge is the gall causing these swellings on the leaves of Hop Trefoil, Trifolium campestre, on which I have again drawn a blank. There is little enough on possible galls for this plant, one candidate being the mite Dasineura trifolii but the description of this refers to folding of the leaves along the mid-rib which is not that evident here. Again, any insights from readers would be helpful. 

Gall on Hop Trefoil

Orchids and Pearly Everlasting
A walk near Treorchy in late June was something of a revelation. A forestry track which starts just north of Cwmparc SS 9472 9617 by a metal barrier is worth trying because of the profusion of Southern Marsh orchids. Up to this point we had been walking through heavily sheep-grazed turf and the only plant you tend to find is Tormentil, Potentilla erecta, although it was interesting to note that Lady's Mantle, Alchemilla sp., was growing in clumps suggesting it is unpalatable even to the voracious sheep. Once into the sheep-free area the botany was a revelation. One of the usual suspects was Pearly Everlasting. The following extract is from a field trip in 1994 to Kenfig by The Wildflower Society:
'Then we came to a first record for Britain, Anaphalis margaritacea, Pearly Everlasting, which was recorded in the South Wales valleys in the seventeenth century and is now spreading over Wales.'
It is certainly quite common in the Valleys, is visible on the edge of the M4 around the Pyle turn-off and turned up on Coppet Hill near Goodrich growing under bracken. Despite its local ubiquity it is almost completely ignored by wildflower books. Wouldn't it be nice to know more about this plant?

Pearly Everlasting

A smattering of Common Spotted Orchids, Dactylorhiza fuchsii, was eclipsed by the Southern Marsh Orchids Dactylorhiza praetermissa which appeared to favour the damper runnels alongside the forestry track and stretched for a mile or more giving one of the best displays you are likely to come across in this part of the world.

Southern March Orchid

Bruce McDonald

Photos by Bruce McDonald

Friday, October 23, 2015

Lichens - short course in Wenvoe

Wenvoe Wildlife Group have organised a short course on Lichens on Saturday 14th November.

It is just two hours: from 10.30am to 12.30pm.

It will start with an indoor introduction to Lichens, before we go out to see which ones we can find in Wenvoe.

No experience necessary - this is ideal for anyone wanting to find out about these fascinating life forms.

It will be led by Barbara Brown of the Natural History Museum's OPAL project.

Anyone can come and the course is free, but places must be booked.

To book and for further details e-mail:

Monday, October 19, 2015

Hedgehog Rescue and Conservation


We had an absolutely wonderful talk last Monday on Hedgehog rescue and conservation by Erica Dixon from 

She was helped in the talk by Poppy the hedgehog who is an unfortunate victim of an accident and has been blinded though a bad head injury, but is otherwise healthy. You can see Poppy being posed for in the pictures below (of course with her injury she was not aware she was being photographed)

The work that the helpline do is wonderful and we had some facts about them and how they were born with spines, and some fascinating information on how you care for an animal that is only days old. It takes a lot of dedication !

We were all then very sad to hear just how much they were needed to be called on given how rare hedgehogs are getting.  Hedgehogs were abundant throughout Britain, with an estimated population of perhaps 30 million in the 1950s. By 1995, the population was estimated to be only about  1.5 million and declining again since then

We were shown some awful pictures of injured animals and we had a very apt reminder of the need to check bonfires before being cheered up with some pictures of success stories and happy hogs being released.

Poppy as has been said is not able to be released so she is being kept to entertain people like us on an occasional basis and spends most of her time in a nice secure garden. She was happy to be awake because with no eyes she has lost perception of the time of day.

All in all a fascinating talk and I know a number of our members exchanged information about being a release site or becoming a helper. if you want more information then take a look at their website

Monday, October 12, 2015

Zoe Melvin wins Bioscience Prize 2015

Bioscience Prize 2015

The Bioscience Prize is awarded annually by Cardiff Naturalists' Society in the memory of former member Prof Ursula Henriques, for the best 2nd-year fieldwork project in the Bioscience Department at Cardiff University. Andy Kendall presented Zoe Melvin with the 2015 award (below) at the CNS meeting on Monday 28 Sept, during which Zoe gave a talk about her project on mosquitoes in Borneo. Zoe has written an article, based on her talk, which will feature in the next CNS newsletter.


Wednesday, September 30, 2015

The Curious Case of the Shrinking Violet

by Bruce McDonald

Vaguely familiar? You know how it is, you see something that rings a bell but you can't quite put a finger on it. In amongst the dunes between Rhossili and Broughton beaches on Gower were some low patches of a plant shown in the photo. Some individual plants, some clumps with trailing stems. Not much to go on so take a photo and consult the books. Nothing obvious in the books so have a look at the photos. A few pieces (small - just 2 millimetres) of something withered and rust-coloured. Close-up on these - just shrivelled, well, could be anything. Hang on - alongside these a flower! Tiny - I could not even see them when looking at the plants in the dunes. Quite distinctive but odd. Back to the books - nothing.

Call in the experts. A quick response from Julian Woodman - some sort of Violet. Of course; no wonder the leaves were familiar. Also a little way back along the flower stem a couple of very small bracteoles - another Viola clue. More research - possibly a hybrid? There are tables of hybrids on the Wildflowerfinder website. But nothing really fits the bill. And the odd puzzle - if they were hybrids would one not expect to see some parent plants around? Find an Oxlip (the hybrid) and you are bound to see some Primroses and Cowslips in the vicinity. But here - nothing. The only Violas were Wild Pansies and they bore few resemblances to our specimens. So, back to the dunes for some further observations.

Another observation. On one plant a seed pod - suggests viability.

A rough count. About 30 plants in an area of 20 square metres - they seem to be prospering. Another look at the stems - runners! But are they rooting?

Take a small plant and tease it out of the sand - possible rhizome?

All the plants seem to be like this - are they all connected? Short of digging up a couple of sand dunes we will not know.

Hmmm! Where now? More Google delving and then, Eureka! A website image of a flower looking very similar to ours and the magic word 'Cleistogamous'. Wikipedia is on hand to clarify - 'Cleistogamy or automatic self-pollination describes the trait of certain plants to propagate by using non-opening self-pollinating flowers. Especially well known in peanuts, peas and beans this behavior is most widespread in the grass family. However, the largest genus of cleistogamous plants is actually Viola' - voila! The opposite is Chasmogamy with open flowers, nectar and pollen but this is relatively expensive in terms of energy.

Wiki goes on to comment that Cleistogamy often occurs in unfavourable sites or adverse conditions. Heavy grazing by livestock or deer or shortage of light may bring on a bout of self-pollination. So the probability is that these violets have become Cleistogamous  because they are growing in nutrient-poor sand-dunes.

Where next? Take a specimen and grow it on in a more nutritious loam - if 'normal' violets appear that will tend to support the argument as well as helping to clarify which variety this is. Also check earlier in the year to see if they do produce conventional flowers in the dunes before reverting to Cleistogamy late Summer. 

Text and Photos by Bruce McDonald

Monday, September 7, 2015

Newsletter 105 is now online

It went to members a few weeks ago, and is now offered more widely in the hope that you will find something of interest and will want to join us at one of our indoor meetings or outdoor events

you can find it by CLICKING HERE 

Tuesday, June 23, 2015

Tortworth Arboretum

By Bruce McDonald

With just a few days to go before our trip to Tortworth, on Sunday 31 May, the weather forecast was dire - would it go ahead? In the event the weather relented and we enjoyed a day at this amazing arboretum led by the irrepressible Tony Titchen, an ideal guide for this collection as he had been involved with the identification and cataloguing of the trees in the past. We had invited members of our other groups and were delighted to be joined by representatives from Bristol Naturalists, Gloucester Naturalists and Friends of Dyffryn Gardens.

For those unfamiliar with the location, the arboretum is in the grounds of the Tortworth Court Hotel near Wotton under Edge and a convenient 45 minute drive from Cardiff. There is plenty of history to this place as Tony pointed out. As far back as Edward I's reign (1272 - 1307) the manor of Tortworth belonged to Sir Nicholas Kingston. The Veel family held it for 200 years when it included a deer park; then the Throckmortons and finally the Ducie family who owned it for 350 years. The house itself was built between 1849 and 1853 by the 2nd Earl and was designed by Samuel Teulon. During the Second World War the building was used first by Royal Navy as a training establishment when it was referred to as HMS Cabbala. Next, American servicemen took up residence and it was at this point that some of arboretum trees were lost due to the spillage of vehicle oil. In 1991 the house was bought by Phillip Stubbs but a disastrous fire caused widespread damage. The structure was then purchased by Four Pillars Hotels and their restoration is what you see today.

And now to the purpose of our visit: the arboretum itself. Whilst some mature trees predate the arboretum it was the 3rd Earl who started planting in 1853 and created an arboretum which at the time was a rival to Westonbirt. Our tour started with a Robinia pseudoacacia (below) but this was the contorted form 'tortuosa'. Robinia originates in the Eastern and mid-Western USA arriving in Europe in the 17th Century.

Then a Blue Cedar, Cedrus atlantica, the form 'glauca' of the Atlas Cedar from the Atlas mountains of Morocco and Algeria. Tony pointed out the characteristic short needles which contrast this cedar with most others. And then a massive Southern European Plane, Platanus hispanica, often referred to as a London Plane. The girth was impressive although, as with many of us, the bulk had shifted downward in old age.

A Dawn Redwood, Metasequia glyptostraboides, followed, discovered in China as recently as 1941. This can be confused with the Swamp Cypress, Taxodium distichum, alongside which it is often planted but a simple key is the opposite foliage of the Dawn Redwood and alternate of the Swamp Cypress. The first Champion tree to grab our attention was a Nikko Maple, Acer nikoense with distinctive trifoliate leaves.

A Shagbark Hickory followed (above), Carya ovata, from North America, and one of 7 different species but distinguishing them can be tricky. However it usually (but not exclusively!) has 5 leaflets whereas the Mockernut and Shell-bark Hickory - the other two with large leaves - usually have 7.

An Oriental Spruce (above), Picea orientalis, was obligingly sporting some cones - Tony reminded us to look out for the unusually short needles on this tree. Many of the trees were supporting Mistletoe including species which were quite unexpected such as the Red Oak, Quercus rubra. A stream marked a valley fault line with acid soil to one side and the other alkaline, helping to enable such a wide variety of tree species to flourish.
Although the rain had held off Tony marched us under the umbrella-like cover of a Crimean Pine, Tilia euchlora, making it a perfect place to shelter from adverse weather (above). A Common Walnut, Juglans regia, provided Tony with an opportunity to use his penknife test to reveal the interrupted pith in the twigs. And a close relative of the familiar Sycamore and similar in appearance was Van Volxem's Maple, Acer velutinum var. vanvolxemii. - a rare tree coming from the Caucasus in the late 19th century. Under it were hundreds of small seedlings - a propagation opportunity if ever there was one. Another rarity followed, Chinese Zelkova, Zelkova sinica, with orange-pink bark.
Next, and sporting the largest leaves we were to see on a tree that day, was an Amercian Lime (above), Tilia americana, and yet another rarity, although it was discovered in North America as far back as 1752. The photo illustrated the size of the leaves as the ruler help alongside was 30 cm or 12 inches long.

Tony took great pains to describe our next tree as the Tree of Juda, Cercis siliquastrum, and not the Judas Tree although it is commonly called the latter. A tree originating in what might loosely be called Judaea is a more logical name than yet another of the many varieties of tree on which Judas is supposed to have hanged himself. Distinguishing this from the not dissimilar Katsura is helped by the fact that the Katsura has opposite leaves and the Tree of Juda alternate.
Sophora japonica was next in line with the common names of the Pagoda or Scholar's Tree. This has similarities with the Robinia that was the first tree on our quest although the latter usually has spines and round-tipped leaflets. An American Blackjack Oak, Quercus marilandica (above) took us nicely up to lunch. With most of our brains and notebooks full to overflowing, how might we cope with the afternoon session?
After a brief pause and cup of tea in the hotel for some we assembled around what must be one of Tortworth's crowning glories, a mighty Caucasia Elm, Zelkova carpinifolia (above). The photo was taken in December and shows the scores of stems twisting up from the ground. Another unusual feature was that the suckers around the base had been trained to form a protective hedge.

The umbrella form of a Pendulous Beech, Fagus sylvatica var. pendula allowed ample scope for the whole group to assemble within its protective canopy (above), before we moved on to a smaller tree with prominent spines, Aralia spinosa, commonly known as the Devil's Walking Stick (below).
Next, an English Oak, Quercus robur, but this was an uncommon variety with variegated leaves. And as if we had not already encountered a plethora of rare trees our next specimen is described as 'very rare' and this was the Chinese Cork Oak, Quercus variabilis, with, as the name suggests, thick, corky bark.
A Willow-leaved Pear, Pyrus salicifolia (above), was showing off some of its small, inedible fruit but our final meeting was with a small tree or large bush that many will have encountered, the Corkscrew Hazel, Corylus avellana var. contorta (below). However this one was different from those that most of us will have come across as it was an 'original'. The story goes that it was first discovered in a hedgerow in Gloucestershire and the 3rd Earl of Ducie was a recipient of one of a number of plants propagated from suckers and distributed to private collections. The Corkscrew Hazels that are available in garden centres at modest cost will all have been grafted as the bush will not grow true from seed or cutting. It also has a popular name, Harry Lauder's walking stick supposedly because the great music hall entertainer often appeared with a crooked walking stick.
With our thirst for trees now well sated our gentle stroll back took us past a pets' cemetery (below), a tunnel of Wisteria (below) and a pudding stone to be greeted by a lively, colourful and exuberant Indian wedding taking place at the hotel.
Our thanks, as ever, to our guru for the day, Tony. If you are tempted by this and love trees why not pop in and wander round the grounds. The hotel will not mind but note that dogs are not allowed. Next year we are planning a return trip to Pontypool Park with Tony as our previous visit was largely washed out. Watch this space for details.
Text and all photos: Bruce McDonald




Friday, June 19, 2015

Peterstone Super Ely

The 25th of May turned out to be a wonderful day for a walk with friends

We went on a route picked out by Rob and Linda Nottage around Peterstone Super Ely

The wildlife abounded in the late spring sun and we were treated to a nice selection of habitats to wander through

The birders amongst us watched out for life as we crossed the river, but I failed to spot anything moving that fast. However I did find some Green Dock Leaved Beetles (Gastrophysa viridula) so engrossed that they did not care when I turned their leaf over.

She's heavily expecting so soon the  larvae will be turning the leaves into something that looks like a fine lace doily. I suspect the small brown pile behind them is exactly what it looks like - frass is the technical term

We wandered along the riverbank and spotted this nice mature Horse Chestnut (Aesculus hippocastanum) or conker tree to the young at heart. This part is overhanging the river so whoever collects these will need to be careful

Oh well when they've had enough exercise collecting the conkers they can rest on this well placed bench 

No good for us though, so we headed from the riverbank into meadows and were soon admiding many wildflowers. Whilst the rest of the team were marvelling at Monkshood I was admiring this Comfrey (Symphytum officinale)

 And a nice yellow Flag Iris (Iris pseudacorus) looking cheerful in the sunshine

And on to open landscapes where we hunted in vain for Sand Martins. not a good show this year, we hope they all found somewhere nice to nest. 

The whole of this flood plane is covered in the most wonderful meanders. Its not possible to do them justice in a picture taken at ground level.  Hmmm  I wonder if can I get permission to drive my land Rover here as a photo platform?

Others were making proper records of what they saw, but I hope some like this simple photo diary of my day out

Excellent company, excellent wildlife, excellent landscapes


Monday, May 11, 2015

Mary Gillham talk by Andy Kendall in Penarth - 21 May 2015

Born in 1921 she was one of the leading naturalists in Wales.  After gaining her doctorate in agriculture and botany at Aberystwyth University, she specialised in island ecology, studying the Welsh islands before moving on to lecture in Britain and abroad.  She was one of the first women scientists in Antarctica and worked on penguin islands in South Africa.  From 1961 she lectured at Cardiff University leading field trips in Britain and abroad, and was a lifelong supporter of Flat Holm.
A talk by Andy Kendall of Cardiff Naturalists' Society
To be held in Room 3, The Kymin, Beach Road, Penarth
Thursday evening at 7pm, May 21st 2015
Suggested donation towards costs of £2/£3
www.flatholm                  Help save Flat Holm          

Tuesday, March 24, 2015

Wallace and Svalbard

You may be forgiven for thinking what's the link between those two as there isn't (to the best of my understanding) any record of the great Naturalist Alfred Russell Wallace going to the frozen north, in fact he's more famous for his trips to the Amazon and the Malay Archipelago

The simple fact is that we had two talks last night and the title reflects the subjects of them both

Julian Carter of the National Museum of Wales led off with his personal account of how he had learned about Wallace during the design and build of an Exhibition that was on at the museum and is now. From the description of that exhibition
On his death 100 years ago, Alfred Russel Wallace was widely praised as the 'last of the great Victorians'. But who was he?
Wallace was many things - an intrepid explorer, a brilliant naturalist, a social activist, a political commentator – overall a remarkable intellectual. In his time, he collected over 125,000 animal specimens, published more than 800 articles and wrote 22 books.
Wallace is most famously associated with co-discovering the process of evolution by natural selection alongside Charles Darwin. Yet we have all heard of Darwin, whilst Wallace has become more of a forgotten figure.
It seems to me that Wallace had a fascinating (if at times stressful) life and contributed to many things such as mapping and surveying the world in addition to his seminal work on evolution.

Joan Andrews one of our past presidents then talked to us about a trip to Svalbard that she and another of our past presidents Tricia Woods took in 2014 and showed a range of photographs of the various wildlife that she had encountered. I was impressed by how close they had been able to get to some Polar Bears, Walrus and many of the birds, and wish I'd been there with my camera

That was the last of our indoor meetings for the season so we will be focused on going out and seeing some wildlife across the summer whilst our 2015/16 programme  is developed - look out for it towards late summer, but please come back here and also take a look at, and join in the other information sources we have on-line and try and join us at one of our outdoor events


Wednesday, March 18, 2015

Neil Price: Hemiptera: The Real Bugs

Dr Neil Price, an entomologist working for David Clements Ecology Ltd, talked to the Cardiff Naturalists’ Society on Tuesday 17 March 2015 about the Hemiptera. This order of insects is also known as the true bugs.  They are characterised by distinctive and elongated mouthparts, designed for piercing and sucking. They mainly feed on plants, but many species are predatory.

We were introduced to a number of bug families within the sub-order Heteroptera. There were some familiar shield bugs, an ant-mimicking mirid bug, seed bugs, and bed bugs. Bugs can have distinct smells and can often be noisy (stridulation). Neil recommended an online identification guide for the identification of British Hemiptera:

There are a variety of ways to survey for Hemiptera: sweep nets, pooters, beating vegetation over trays, light traps, and large expensive-looking vacuum-cleaner devices. Neil has recently been involved in sampling Hemiptera on brownfield sites (land altered by human activity, especially post-industrial areas). These areas are increasingly being recognised as important for wildlife, and may be home to around 12-15% of Britain’s rare insects.  Brownfield sites have micro-habitats favourable to many insects, including bare loose substrates, short vegetation and scrubland.

Survey work on four brownfields sites within Buglife’s West Glamorgan Stepping Stones project revealed a diverse range of Hemiptera.  Neil talked about the species encountered on four of the five West Glamorgan brownfield sites: Pluck Lake in Swansea (25 species), and Bryn Tip (19), Cymmer Coal Tip (21), and a site within Tata Steelworks (14), in Neath Port Talbot (NPT). The project is monitoring invertebrates, reptiles and plants and aims to restore and manage a total of 48 hectares of brownfield habitat.

Finally, Neil told us to be on the look-out for the Western conifer seed bug (Leptoglossus occidentalis), a large invasive squashbug species from North America that feeds on pines. It was introduced into Europe in 1999, and is spreading along the south Wales coastline.

You can report Western conifer seed bug findings here:

Buglife's West Glamorgan Stepping Stones project:

Wednesday, March 11, 2015

Track a Tree

An invite from our friends from the North... 


click on the poster for a larger version 

Tuesday, February 17, 2015

In Search of the Wildcat

At last night’s (16/2/2015) meeting, Chris Hatch gave an illustrated talk about the wildlife of the Scottish highlands. Chris is a self-employed ecological consultant based in South Wales, who works as a wildlife photographer and as a world-travelling wildlife tour leader. He is part of the Wild Media Foundation, a company that uses photographic images to draw attention to nature conservation issues.

Chris started his photographic tour on the high mountains of the Cairngorm National Park, with ptarmigan and arctic hare. These hares are killed in large numbers by gamekeepers in the highlands, because they can pass on tics to grouse (hunters pay up to £1,000 per day to shoot grouse on the big estates). The moorlands below the peaks were the setting for spectacular images of merlin, hen harrier, black grouse and other wildlife.

We detoured to the Moray Firth, to look at seals, bottlenose dolphin, puffin, gannet, artic tern and other seabirds; accompanied by interesting facts on the threats some of these species face. On the positive side, white-tailed sea eagle and other species are benefitting from reintroduction programmes, which in combination with eco-tourism initiatives benefit the local economy.

Back in the Cairngorms, ospreys are fed fish from a local fish farm near a hide in one eco-tourist location. Chris showed photos of a range of birds encountered in the pine forests, including the large capercaillie which feeds on pine needles. The pine forests are also a stronghold for the red squirrel, one of Chris’ favourite animals to photograph.

Chris took many of his bird of prey shots in the Cairngorms using a make-shift hide and bait taken from a friend’s roadkill-stocked freezer. This is also how he eventually managed to get his shots of the elusive Scottish wildcat, which is seldom photographed in the wild. The wildcat is a powerful animal, about half-the-size-again of the largest domestic cat. Its main distinguishing feature is its blunt rounded tail with dark bands around it. The Scottish wildcat is a sub-species of the European wildcat and its population is down to around 400 individuals in total; with the main threat being inter-breeding with female domestic cats. A charity “Highland Tiger” is helping to save the Scottish wildcat, with one of its main aims being to get people to neuter their domestic cats.

Find out more about the Wild Media Foundation here:

Highland Tiger – saving the Scottish wildcat:

Saturday, January 31, 2015

Members evening

Once again a wonderful set of talks from the members of the society about all sorts of things

I never fail to be entertained on these evenings and the best thing is getting ideas of places that we'd like to go and see ourselves and things we'd like to learn about if we had time

We had Christine and Paul with Cyprus and Morocco respectively and Phill with a whirlwind tour of Northern Europe's top sites. Linda entertaining us with how you can use the new books that are coming out to review and revise the things you have previously identified Barbara enticing us to visit the Ger region of France with some of the wonderful scenery (and apparenrtly food & drink ) of the area

Oh! and I followed up with some California girls (and boys)

Wednesday, January 21, 2015

Tidal Lagoons in south Wales

Last night, I went to a presentation given by Tidal Lagoon Power at the Penarth Pier Pavilion. This was part of an evening organised by Gwyrddio Penarth Greening (PGP). I will give a short briefing here on tidal lagoon developments in south Wales.

Joanna Lane, the Wales Public Affairs Manager of Tidal Lagoon Power Ltd, talking about the proposed Swansea Bay Tidal Lagoon and plans for further tidal lagoons in four areas around the coast of the UK (Severn, Thames, west coast of NE England into Scotland, and The Wash), including a proposed tidal lagoon between Cardiff and Newport.

The final planning decision on the Swansea Tidal Lagoon will be made this summer (June 2015). If successful, work on site will begin this September, with a two-and-a-half year build envisaged. The technology is ingenious (see the video:, but both the turbine and construction techniques are well-tried and tested elsewhere (e.g. the Netherlands). At Swansea, a 9.5 km breakwater wall will enclose a tidal area of around 11.5 km2. Water will be held in the lagoon on the outgoing tide and kept out on the incoming tide. Given two tides, electricity will be generated four times a day as the water released in both directions drives 26 low-head bulb turbines. The power generated will be equivalent to 90% of Swansea’s domestic use. The lagoon infrastructure is designed to generate this power for at least 120 years. The proposal incorporates plans for 10 km of marine ecosystem restoration and mariculture (e.g. mussels, oyster, samphire, seaweed, and possibly algae for biofuel in collaboration with Swansea University).

Tidal Lagoon Power’s business model depends on the eventual completion of six tidal lagoons, which will generate around 8% of the UK’s electricity. Locations around the UK enable differences in the timings of the tides to be exploited, so that demand can be met around the clock. The other lagoons will be considerably bigger than the one in Swansea, as this first UK tidal lagoon is also acting as a demonstration project for future developments and a starting point for a new tidal power industry. Different considerations will come into play at each proposed site. At Swansea, for instance, no rivers enter the lagoon, it backs onto a brownfield site (Swansea University is building its new campus on part of this site), and there is a focus on providing public access and civic amenities (e.g. sports).

The proposed tidal lagoon between Cardiff and Newport (tidal range 9.2 m) will have a breakwater wall running for around 20-25 km, enclosing a tidal area of around 70 to 80 km2. The tidal range will be converted to electrical power using 60 or 65 turbines. It is likely to extend from the coast around 2 km from Cardiff Bay to around 2 km from the mouth of the River Usk in Newport. This lagoon is likely to be more problematic from the environmental impact assessment point of view than the one in Swansea, because the river Rhymney may flow into it and it will incorporate wetlands. Some of this area is of conservation importance at the European level, which will oblige Tidal Lagoon Power to create compensatory habitats in collaboration with Natural Resources Wales. The company acknowledges that this is a “new science”, and that importance lessons can be learned from the Cardiff Barrage experience.

A pre-application for the Cardiff and Newport Tidal Lagoon has just been submitted (November 2014), with a full planning application expected around 2017 and a goal of generating power around 2021. There is an opportunity for the Cardiff Naturalists' Society and similar stakeholder organisations to get involved at an early stage of this proposal.

Stephen Nottingham
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